Door mounting



April 24, 19 G. HOPKINS 3,030,656

DOOR MOUNTING Filed May 14, 1959 3 Sheets-Sheet 1 FIGB.

8 LzLAm o n sKms H64. Q WT ATTORNEY April 962 G. HOPKINS 3,030,656

DOOR MOUNTING Filed May 14, 1959 3 Sheets-Sheet 2 INVENTOR LELAND G.HOPKINS BYWXW ATTORN EY A ril 24, 1962 e. HOPKINS DOOR MOUNTING 3Sheets-Sheet 3 Filed May 14, 1959 FIGH.

INVENTOR LELAND G. HO KI S amwxw v ATTORNEY 3,036,656 DGQR MQUNTINGLeland G. Hopkins, Mansfield, Ohio, assignor to Westinghouse ElectricCorporation, East Pittsburgh, Pa., a corporation of Pennsylvania FiledMay 14, E59, Ser. No. 813,248 3 Claims. (Cl. 16-147) This inventionrelates to closure mountings, more particularly to mountings for doorsof domestic ovens and the like, and has for an object to enable an ovendoor to be pivoted about a horizontal axis and about a vertical axis,selectively.

For many years, oven doors were pivoted to open about a vertical axisadjacent one side of the door, this method of mounting the doorpermitting the housewife to stand or kneel close to the oven whencleaning the latter or when reaching into the rear portion of the ovenfor any reason. In recent years, most oven doors have been mounted forpivotal movement about a horizontal axis adjacent the bottom of thedoor, so that, when opened, the door functions as a shelf extendingforwardly from the oven bottom wall for support of foods and cookingvessels before being placed in the oven or upon being removed therefromfor inspection or for serving.

Such horizontally-pivoted doors have the disadvantage that they preventthe housewife from standing directly in front of, and close to, the ovenwhen cleaning the latter or when reaching into the rear portion thereoffor any reason.

The present invention enables the housewife to obtain the advantages ofboth known types of door mountings, While avoiding the disadvantagesthereof. To this end, the invention provides mounting means for an ovendoor such that the door may be pivoted about a vertical axis and about ahorizontal axis, at the will of the user. In one form of the inventionan oven door handle is movable between two positions to selectivelyrender effective the pivots for one axis or the other. In one positionof the handle the door pivots about a vertical axis and in anotherposition of the handle the door pivots about a horizontal axis. Inanother form of the invention the door handle may be stationary, andshifting of the efiective pivots effected by a manually operable latch.

Another object of the invention is to facilitate cleaning of an oven ofthe type in which the door is utilizable as a shelf.

A further feature of the present invention is the provision of a torsionbar, housed within the door structure, for applying to the door, as itis opened, a biasing force tending to urge the door toward closedposition. Such an arrangement for counterbalancing the weight of theoven door is particularly useful with wall ovens and stacked ovens whichhave no free space therebeneath for location of the usualcounterbalancing springs.

Another object of the invention is to provide oven door counterbalancingmechanism for ovens which are so located that no space is availabletherebelow for the usual counterbalancing mechanism.

Yet another object of the invention is the provision of an oven doorcounterbalancing mechanism which may be housed within the oven doorstructure.

The foregoing and other objects are effected by the invention as will beapparent from the following description and claims taken in connectionwith the accompanying drawings, forming a part of this application, inwhich:

FIG. 1 is a perspective view of a free standing range whose oven door ismounted in accordance with the present invention, the door being shownpivoted to open position about a horizontal axis adjacent its loweredge;

FIG. 2 is a similar view of the same range with the door $63,656Patented Apr. 24, 1962 pivoted to open position about a vertical axisadjacent one of its side edges;

FIG. 3 is an enlarged perspective view of a portion of the structureshown in FIGS. 1 and 2, with the oven door closed and with portions ofthe door front panel broken away to more clearly illustrate mechanismhoused within the door;

FIG. 4 is an enlarged fragmentary sectional view taken along line IVIVof FIG. 3, looking in the direction indicated by the arrows;

FIG. 5 is an enlarged fragmentary sectional view taken along line VV ofFIG. 3, looking in the direction indicated by the arrows;

FIG. 6 is an enlarged fragmentary sectional view taken along the lineVIVI of FIG. 3, looking in the direction indicated by the arrows;

FIG. 7 is a fragmentary sectional view similar to FIG. 6, but showing aportion of the mechanism pivoted to a different position;

FIG. 8 is an enlarged fragmentary sectional view taken along lineVIIIVIII of FIG. 6, looking in thedirection indicated by the arrows;

FIG. 9 is a fragmentary side elevational view of the keeper elementshown in FIGS. 6, 7 and 8.

FIG. 10 is a fragmentary perspective view similar to FIG. 3, but showinga modified construction.

FIG. 11 is a fragmentary sectional view taken along the line XI-XI ofFIG. 10, looking in the direction indicated by the arrows;

FIG. 12 is a fragmentary vertical sectional view taken along the lineXII--XII of FIG. 10, looking in the direction indicated by the arrows;

FIG 13 is a fragmentary vertical sectional view taken along lineXIII-XIII of FIG. 12, looking in the direction indicated by the arrows;

FIG. 14 is a fragmentary vertical sectional view taken along lineXIV-XIV of FIG. 12, looking in the direction indicated by the arrows;

FIG. 15 is a fragmentary sectional view similar to FIG. 13, but showingthe door in a horizontal position;

FIG. 16 is a fragmentary front elevational view of the upper right-handcorner of the structure shown in FIG. 10; and

FIG. 17 is a fragmentary sectional view taken along line XVIIXVII ofFIG. 16, looking in the direction indicated by the arrows.

In FIGS. 1 to 9 there is shown a free standing range having an oven 10in the upper portion thereof and a storage drawer 11 below the oven. Theoven 10 is defined by top and bottom walls, side and rear walls and afront wall 12, the front wall 12 having an opening 13 therethroughproviding access to the oven 10. The access opening 13 is provided witha closure in the form of a door 14 having novel structure for mountingthe same on the oven front wall 12 so that the door may be moved betweenclosed and open positions about either a horizontal axis adjacent itslower edge or about a vertical axis adjacent one of its side edges, asselected by the user.

In order to effect this novel pivotal arrangement there is provided apivot structure 16, at the lower left of the door as viewed in FIGS. 1,2 and 3, which functions only when the door pivots about the horizontalaxis; a pivot structure 17 at the lower right of the door, whichfunctions during pivotal movement of the door about both the horizontalaxis and about the vertical axis; and a pivot structure 18 at the upperright-hand corner of the door, which functions as a pivot only duringpivotal movement of the door about the vertical axis.

The invention includes the provision of pivot-adjusting mechanism 19associated with the pivot structure 16 and pivot-adjusting mechanism 20associated with the pivot structure 18, together with manually operablemeans 21 for rendering effective the two adjusting means 19 and 20,selectively at the will or the user, so that as one pivot is renderedeffective, the other pivot is rendered ineffective, and vice versa.

Referring now particularly to FIGS. 3, 6, 7'. and 8, the door 14includes spaced parallel front and rear panels 22 and 23, respectively,joined at' their edges by a peripheral wall 24, the space betweenthepanels serving tohouse the pivot structures 16, 17 and 18 and also thepivot adjusting mechanisms 19 and 2t).

The pivot structure 17, at the lowerright-hand corner of the door, asviewed in FIG. 3, functions during both horizontal pivoting and verticalpivoting of thedoor and, in the construction herein illustrated,comprises a socket 26 mounted on the front wall 12 of the oven andextending through an appropriate opening in the door rear panel 23. Thesocket 26 rotatably receives the mating ball portion 27 housed in thespace between the door panels and carried at the free end of a leg 28 ofan inverted U-shape loop 29 whose other leg 30 constitutes a rightangled extension of a torsion bar 31 which extends transversely of thedoor substantially along the horizontal axis about which'thedoorpivots.The inverted U-shape loop 29 is anchored within the door by suitablemeans, such as the bolt 32, sleeve 33, and flanged collar 34, best shownin FIG. 4.

As best shown in FIG. 5, the opening in the socket 26, through which aportion of the ball 27 and its associated leg 28 extend, lies in a planedisposed at substantially 45 with respect to the vertical in order thatthefleg 28 may extend vertically with respect to thesocket when the dooris closed, or when it is pivoted open about the vertical axis, and mayextend horizontally, as indicated by dot-dash lines, when the door isfully opened about the horizontal axis.

Considering now the pivot structure 16,. shown at the lower left-handcorner of the door as viewed in FIG. 3, it will be seen that theleft-hand end of the torsion rod 31is bent through 180 to provideaU-shaped terminal portion 35 whose legs are comprised by the'free leg 36and the extreme left-hand portion 31a of they torsion rod 31. Theleft-hand end of torsion rod 31, and its U-shaped terminal portion 35, Jare supported with respect to the door by reception of portion 31a ofthe .torsion rod within the loop 38 of a stepped strap 39, which isrigidly secured to the rear panel 23 of the door. The pivot structure 16includes, in addition to the U-shaped. terminal 35 of the torsion rod, akeeper 41 permanently secured to the oven front wall, 12 by a lateralflange 42. The keeper includes a pair of vertically spaced arms '43 and44 lying ina common vertical plane disposed normal to the front wall ofthe oven, the vertical spacing of the arms 43 and 44 providing aforwardly opening notch 45 therebetween which is adapted to receive thefree, leg 36 of the U- shaped terminal 35 of the torsion rod 31. Asshown in FIGS. 6 and 9, the lower arm 44 of the keeper is provided' withan upwardly opening notch 47 for reception of the other. leg 31:: of thetorsion rod terminal 35.

As best indicated in FIG. 6, by the dot-dash showing, the U-shapedterminal portion 35 of the torsionrod 31, when unrestrained by thekeeper, .lies in a plane inclined upwardly and rearwardly, with theresult that the leg 36 is normally disposed rearwardly and slightlyabove the other leg 31a when the door is open. Byreference to FIG. 6, itis apparent that when the door is swung about its vertical axis fromopen position to closed position, the leg 36 of the U-shaped terminalportion will not be aligned with the notch 45 between the verticallyspaced armsof the keeper. Accordingly, the outer or forward end of theupper arm 43 is inclined downwardly and inwardly to provide'a camsurface 46 which will deflect the leg 36 of the U-shaped terminalportion downwardly into the notch 45 as the door is closed. Since thisdownward deflection of the leg 36 will tend to deflect the other leg 152 as the door pivots about the arm 31a: (FIG. 7).

31a downwardly also, the outer or forward end of the keeper arm 44 isreversely inclined upwardly and rearwardly to provide a cam surface 48for deflecting and guiding the leg 31a upwardly into the notch 47 inwhich it fits when the door is fully closed.

Inasmuch as the leg '36 is biased downwardly with respect to the leg 31awhen the door is closed, it will be apparent that a torsional force isapplied to the torsion bar 31, since the other end of the torsion bar isrestrained against rotation about its longitudinal axis by the retentionof the loop 29 in the space between the door front and rear panels. Thistorsion force acts through the leg 30 at the right-hand end of thetorsion bar, to urge and retain the door in closed position. It will beapparent that when the door is swung to open position, about itshorizontal axis, the torsion force applied to the rod is materiallyincreased, since the leg 3t) will now be disposed horizontally while theloop 35 at the other end of the torsion bar is retained initssubstantially horizontal position by the keeper 41. This added torsionforce is the equivalent of the counterbalancing force normally suppliedto conventional doors by the oounterbalancing springs which are usuallylocated in the space below the oven chamber infree standing ranges.Since such space is not necessarily available in built-in ovens or instacked ovens which are disposed on existing countertops', the presentinvention finds particular utility in such installations by eliminatingthe necessity for any counterbalancing springs which would normally bepositioned below the bottom wall of the oven chamber.

While the twisting action applied to the torsion bar terminal loop 35 bythe keeper 41 normally is suflicient to prevent any accidentalwithdrawal of the loop from the keeper, such accidental withdrawal wouldbe undesirable if the pivot structure 18 at the upper right-hand cornerof the door, as viewed inFIG. 3, were not adjusted to be efiective. Thepresent invention provides, as an additional safety feature, means forpreventing such accidental withdrawal of the loop 35 from the keeper inthe event it is attempted to open the door about its vertical axis whilethe upper vertical axi pivot structure 18 is inefiective. To this end,there is provided a locking rod 49 vertically reciprocable throughaligned openings in one or more supporting brackets 51 (FIG. 3), carriedby the door panel structure, and in the stepped bracket 39. The

lower free end of the locking rod is adapted to be received in anopening 52 provided in a leg- 53 extending laterally from the keeper 41at the bottorn'of the latter. As best shown in FIGS. 6 and 7, thisengagement of the locking rod 49 in the arm 53 will not interfere withpivotal movement of the door about its horizontal axis, since the lowerend of the rod 49 will move upwardly out of the opening In thisconnection, it may be desirable to'chamfer the rear edge of the lowerend of the rod 49, as at St Also, this structure is so designed that thelower end of the rod 49 will clear the other leg 36 of the U-shapedtorsion rod terminal as the door is further lowered into horizontal openposition. The path that the lower end'of the locking rod 49 followsduring opening movement of the door about its horizontal axis asindicated by the solid arrow in FIG. 7. Similarly, the path that therear edge of the door follows, with respect to the front wall of theoven, is indicated by the dotted arrow in that same figure. The lockingrod 49 operates in conjunction with adjustment of the pivot structure18, at the upper right-hand corner of the door, in a manner to behereinafter described.

. Referring now to the pivot structure 18, at the upper right-handcorner of the oven door as viewed in FIG. 3, there is shown a pivot pin55 whose longitudinal axis coincides with the vertical axis. of thedoor. This pivot pin is mounted to reciprocate vertically in asupporting bracket 56 carried by the door structure and is supportedat'its lower end by a link 5? connecting it with one arm of a bell crank58. When the pivot pin is moved upwardly its free end Will extendthrough an opening in the peripheral wall 24 of the door and into analigned opening 60 in the lower surface of the oven top wall. The wallsof this opening 60 function as a bearing for the pivot pin 55 about itsvertical axis.

Since the pivot pin 55 must be retracted or lowered in order for thedoor to pivot about its horizontal axis, and since the locking rod 49 ofthe pivot structure 16 must be moved upwardly for pivotal movement ofthe door about its vertical axis, the mechanism 21 has been provided formaking simultaneous adjustments of these two elements. The mechanism 21includes a disc 62 secured on a rotatable shaft 63 carried by the doorfront and rear panels. A link 64 connects the disc with an arm of thebell crank 58 while another link 65 connects the disc 62 to the bellcrank 66. This latter bell crank is connected by a link 67 to the upperend of the locking rod 49. Since the links 64 and 65 connect to the disc62 at points adjacent the periphery thereof which are sub stantiallydiametrically opposed, rotation of the disc in clockwise direction, asviewed in FIG. 3, will move the pivot pin 55 upwardly into operativeposition and will simultaneously move the locking rod 49 upwardly intoinoperative position to permit the U-shaped terminal 35 of the torsionrod 31 to be disengaged from the keeper as the door i pivoted about itsvertical axis to open position. Conversely, rotation of the shaft 63 anddisc 62 in counterclockwise direction will retract the pivot pin 55 andmove the locking rod 49 downwardly to its locking position within theopening 52 of the arm 53.

While any suitable means may be provided for rotating the shaft 63 andits associated disc 62, the present invention provides amanually-operable handle 68 drivenly secured to the shaft 63 anddisposed forwardly of the front panel 22 of the door, where it may bereadily grasped by the hand of a user. Preferably, the handle is sodisposed on the shaft 63 that, when the handle is in the horizontalposition shown in FIGS. 1 and 3, the adjusting mechanism will haveretracted the pivot pin 55 and locked U-shaped terminal 35 to preparethe door mounting mechanism for pivotal movement of the door about itshorizontal axis. Similarly, when the handle is disposed in verticalposition, as illustrated in FIG. 2, the door mounting mechanism will bepositioned to prepare the door for pivotal movement about the verticalaxis with the pivot pin 55 extended into the opening 60 of the oven topwall and with the locking rod 49 raised to permit disengagement of theU-shaped terminal 35 from the keeper 41.

Operation of Mechanism of FIGS. 1 t0 9, Incl.

When it is desired to open the door by pivoting it about its horizontalpivotal axis, the handle 68 is turned counterclockwise to the horizontalposition shown in FIG. 3, thereby rotating the bell crank 58 clockwiseto retract the pivot pin 55 from its pivotal bearing in opening 60, andsimultaneously rotating the bell crank 66 counterclockwise to move thelocking rod 49 downwardly into opening 52 in the leg 53, thus positivelypreventing withdrawal of the torsion rod terminal loop 35 from itskeeper 41. As soon as the handle 68 has been rotated to its horizontalposition, the door may be pivoted about its horizontal axis with theball 27 rotating in its socket 26 through approximately 90 degrees, asshown in FIG. 5. During this opening movement, the torsion rod terminalloop 35 is held against rotation by the keeper 41. At the same time, theother end of the torsion rod 31, at 30, is rotated through approximately90 degrees, thereby producing in the torsion rod 31 a force offsetting aportion of the weight of the door and urging the door towards closedposition. This force stored in the torsion rod during opening of thedoor about its horizontal pivotal axis corresponds to thecounterbalancing force normally obtained by the use of levers andsprings housed in the range cabinet structure in available space belowthe oven.

Referring now to FIGS. 10 to 17 inclusive; there is,

shown a modified door mounting structure in which the locking rod 49 ofthe previously described embodiment is omitted, as can be safely donewhen manufacturing tolerances are sufliciently strict to insure firmretention of the torsion rod U-shaped terminal portion 35 in the keeper41.

The pivotal structure 16 at the lower left-hand corner of the door isidentical in both constructions, with the exception just mentioned,i.e., the omission of the locking rod 49.

In place of the ball and socket pivot for both horizontal and verticalaxes, there is provided a double acting pivot which includes a loop 71carried at the forward free end of a horizontally extending arm 72 of abracket 73 which is fixedly secured to the front wall 12 of the oven.This loop 71 rotatably supports a short shaft 74 having at one end aloop or eye 75 receiving a pivot pin 76 carried by a bracket 77 which issecured to the door structure. By this construction the door may pivotabout a horizontal axis which coincides with the longitudinal axis ofthe short shaft 74 by rotation of this shaft in the loop or sleeve 71 ofthe bracket 73. When the door is to be swung about its vertical pivotalaxis, the loop or eye 75 of the shaft 74 will swing on the pivot pin 76,carried by the bracket 77. The longitudinal axis of the pivot pin 76coincides with the pivotal axis for the door.

Since the ball and socket construction are omitted in this modification,the means for retaining the right-hand end of the torsion bar 131 may besimplified by providing a simple extension 132 at right angles to thetorsion bar 131, together with a suitable bracket 81 secured to the doorstructure and retaining the free end of the torsion bar terminal 132.Preferably, the right-hand end of the torsion bar 131 is supported bypassing through a loop 78 of a bracket 73 carried by the door structure.

Since the locking rod is omitted in this modification, it is notnecessary to provide any interlock or adjusting mechanism forsimultaneously rendering one pivot effective and the diagonally oppositepivot inefiective. Consequently, the door in this modification isprovided with a somewhat conventional handle 82 extending parallel toand near the upper edge of the door and mounted thereon in the usualmanner by bolts 83 and spacer discs 84 (FIGS. 16 and 17).

The pivot pin 55 at the upper right-hand corner of the door, as viewedin FIG. 10, is positioned at all times in the opening in the upperperipheral wall 24 of the door,

and is supported at its lower end by a pin 85 extending through its eyeor loop 86 and carried by one end of a stepped lever 87, located betweenthe door front and rear panels 22 and 23 respectively. The stepped lever87 is secured to, and supported by, an operating shaft v88 pivotallymounted in aligned openings in the door front panel 22 and in the rearwall of the door handle 82 (FIGS. 16 and 17).

A latch member 89 is carried by the forward end of the shaft 88, whichprojects into the space provided between the front and rear walls of thedoor handle. The latch 89 is non-rotatably secured on the shaft 88 andextends laterally therefrom to the left, as viewed in FIGS. 10 and 16.When the latch 89 is moved downwardly from the position shown in fulllines in FIGS. 10 and 16, where it is concealed within the door handle82, to the position indicated by the dot-dash lines in FIG. 16, thepivot pin 55 is moved from its retracted position shown in full lines inFIGS. 10 and 17 to its operative position shown in dot-dash lines ofFIGS. 16 and 17, where its free end will extend through aligned openingsin the oven top wall and in an overlying bracket 90.

As best shown in FIG. 10, the latch 89 is provided with a finger piece91, disposed forwardly of latch 89, and easily engaged by the finger ofa user by reaching up into the space within the door handle 82, wherethe latch is located.

It will be apparent that, with this construction, the housewife willnormally open the oven door by pivoting it about its horizontal pivotsand for this type of opening movement the horizontally disposed handleis preferable. When it is desired toclean the oven or when the housewifeneedsto stand close to the oven for any other reason, the door may befreely rotated about its vertical pivotal axis by merely pulling down onthe latch 89, thereby rendering the pivot pin 55 operative, and thengrasping the handle 82 adjacent the left-hand end of the door, as viewedin FIG. 9, and swinging the door about its vertical axis.

While the invention has been shown in two forms, it will be obvious tothose skilled in the art that it is not so limited, but is susceptibleof various other changes and modifications without departing from thespirit thereof.

7 What is'claimed is:

1. A vertical wall having an opening therethrough, a rectangular doorfor said opening, means mounting said door for pivotal opening andclosing movement selectively about a'horizontal axis adjacent its loweredge and about a vertical axis adjacent one of its side edges, saidmounting means including a pivot common to both of said'axes adjacenttheir point of intersection, a torsion rod extending transversely ofsaid door adjacent said horizontal axis, a keeper carried by saidvertical wall and having a notch for reception of a first terminalportion of said torsion rod which is remote from said common pivot, saidkeeper providing a support for said rod during pivotal movement of saiddoor about said horizontal axis and releasing, said rod for pivotalmovement of said door about said vertical axis, said keeper includingmeans for preventing rotationof said first terminal portion of said rodrelative to said keeper during pivotal movement of said door'about saidhorizontal axis, and means restraining the other terminal portion ofsaid rod against rotation relative to said door, whereby pivotalmovement 0i said door about said horizontal axis in the Openingdirection applies a torsional force to said rod tending to elose saiddoor.

2. A vertical wall having an opening therethrough, a rectangular doorfor said opening, means mounting said door for pivotal opening andclosing movement selectively about a horizontal axis adacent its loweredge and about a vertical axis adjacent one of its side edges, saidmounting means including pivot structure for both of said axes adjacenttheir point of intersection, a torsion rod extending transverselyof saiddoor adjacent said horizontal axis, a keeper carried by said verticalwall and having a notch for reception of a first terminal portion ofsaid torsion rod which is remote from said pivot structure, said keeperproviding a support for said rod during pivotal movement of's'aid doorabout said horizontal axis and releasing said rod for pivotal movementof said door about said vertical axis, said keeper including means forpreventing rotation of said first terminal portion of said rod relativeto said wall during pivotal movement of said door about said horizontalaxis, means restraining the other terminal portion of said rod againstrotation relative to said'door, whereby pivotal movement of said doorabout said horizontal axis in an opening direction applies a torsionalforce to'said rod tending to close said door, and a pivot pin carried bysaid door and disposed with its axis coinciding with said vertical axisand adjacent a corner of said door remote from said pivot structure,said pivot pin being adjustable between an operative position where itprojects beyond the periphery of the door and is rotatably received in amating opening in the vertical Wall, and an inoperative position whereit is retracted from said mating opening.

3. A vertical wall having an opening therethrough, a rectangular doorfor said opening, means mounting said door for pivotal opening andclosing movement selective 1y about a horizontal axis adjacent its loweredge and about a vertical axis adjacentone of its side edges, saidmounting means including pivot structure for both of said axes adjacenttheir point. of intersection, a torsion rod extending transversely ofsaid door adjacent said horizontal axis, a keeper carried by saidvertical wall and having a notch for reception of a first terminalportion of said torsion rod which is remote from said pivot structure,said keeper providing a support for said rod during pivotal movement ofsaid door about said horizontal axis and releasing said rod for pivotalmovement of said door about said vertical axis, said keeper includingmeans for preventing rotation of said first terminal portion of said rodrelative to said wall during pivotal movement of said door about saidhorizontal axis, means restraining the other terminal portion of saidrod against rotation relative to said door, whereby pivotal movement ofsaid door. about said horizontal axis in an opening direction applies atorsional force to said rod tending to close said door, a pivot pincarried by said door and disposed with its axis coinciding, with saidvertical axis and adjacent a corner of said door remote fromsaid pivotstructure, said pivot pin being adjustable between an operative positionwhere it projects beyond the periphery of the door and isrotatably'received in a mating opening in the vertical wall, and aninoperative position where it is retracted from said mating opening, andmanually operable means for adjusting said pivot pin to its operativeand inoperative positions. 7

References Cited in the file of this patent UNITED STATES: PATENTS872,694 Thiem Dec. 3, 1907 962,426- Hansen June 28, 1910 1,355,868Trenkamp Oct. 19, 1920 2,539,151 Mills Jan. 23, 1951 2,885,723 AltmannMay 12, 1959 FOREIGN PATENTS 969,259 Germany 1 May 14, 1958 1,081,674France June 9, 1954

